Citations

Immune checkpoint inhibitors (ICIs) and brentuximab vedotin (BV) are novel agents for classic Hodgkin lymphoma, including relapse after autologous stem cell transplant (ASCT). However, their impact on survival post-ASCT relapse, in comparison with conventional therapy, is less known due to the lack of randomized controlled trials. Clinical characteristics and outcomes of 115 patients with relapse (or progression) after ASCT are studied. After a median follow-up of 8.59 years from post-ASCT relapse, the median progression-free survival (PFS) and overall survival (OS) were 0.91 and 5.07 years, respectively. Median lines of therapy after post-ASCT relapse was 2 (range, 1–12). The median PFS was not reached (NR) versus 1.11 versus 0.50 versus 0.85 versus 0.78 years (P = 0.006) and OS was NR versus 7.60 versus 3.08 versus 3.51 versus 3.17 years (P = 0.28) in patients first treated with ICIs versus BV versus investigational agents versus chemotherapy versus radiation therapy (RT). First-line treatment with novel agents (ie, ICIs and BV) was associated with superior outcomes compared with investigational agents and chemotherapy/RT with a median PFS of 1.65 versus 0.50 versus 0.79 years (P = 0.003) and a median OS of 7.60 versus 3.08 versus 3.32 years (P = 0.08). Regardless of lines of therapy, the treatment with ICIs had the most favorable outcome with a median PFS and OS of 3.98 and NR years, respectively. Allogeneic stem cell transplant (allo-SCT) was done in 23 patients (20%), and the median post-allo-SCT PFS and OS were 1.31 and 2.35 years, respectively. In conclusion, survival following post-ASCT relapse improves significantly when patients receive novel agents.

Abstract Introduction: Rapid cell proliferation requires intact and faithful DNA damage repair mechanisms. DNA polymerase theta (POLQ) plays a key role in repairing DNA double-strand breaks through the microhomology-mediated end-joining (MMEJ), which is one of the three main pathways involved in repairing replication-induced double-strand breaks. Limited data have suggested that concurrent depletion of POLQ and ataxia-telangiectasia mutated (ATM) could be embryonic lethal. Hence, this phenomenon has the potential to be exploited for therapeutic benefit in cancers where ATM mutations are commonly seen. Mantle cell lymphoma (MCL) is a non-Hodgkin lymphoma marked by (11;14) translocation with ATM alterations seen in 40-50% of patients. There is an unmet need to find novel therapeutic strategies, especially in relapsed and/or refractory (R/R) MCL. Here, we investigated whether targeting POLQ and ATM could be a potential therapeutic strategy in MCL. Methods: In vitro studies were conducted by using MCL cell lines. CRISPR-Cas9 system was used to genetically deplete POLQ and ATM genes and sgRNAs co-expressing fluorescence markers were used to track the cell population with respective genotypes over time. Cell viability was assessed by CellTiter-Glo assay and flow cytometry. All cell lines were profiled for ATM expression and activity. A p-value of < 0.05 was considered statistically significant. The combination index of <1 was defined as synergistic. Results: CRISPR-Cas9-mediated depletion of POLQ significantly decreased cell proliferation in multiple MCL cell lines. In particular, Granta-519, which possesses a single copy of kinase-dead ATM that is reduced in expression, was most sensitive to POLQ depletion. Concurrent genetic depletion of ATM and POLQ resulted in a synergistic antiproliferative effect in ATM-proficient MCL cell lines. Subsequently, this cellular phenotype caused by the genetic intervention was recapitulated by using two POLQ inhibitors (novobiocin and ART558) and an ATM inhibitor (AZD0156). In vitro, single-agent treatment with novobiocin or ART558 caused a significant cytotoxic effect at physiologically relevant concentrations in ATM-deficient cells and co-treatment of novobiocin or ART558 with AZD0156 was synergistic in killing ATM-proficient MCL cells. Importantly, POLQ inhibitors significantly decreased the cell viability of MCIR1, which is an ibrutinib-resistant MCL cell line. Mechanistically, novobiocin or ART558 treatment induced gH2AX and cleaved PARP upregulation, which was further enhanced by ATM depletion, suggesting that co-inhibition of POLQ and ATM caused apoptosis due to the accumulation of unrepaired DNA damage. Conclusion: POLQ is a promising target in MCL, especially in ATM-deficient setting. In ATM-proficient MCL, targeting ATM and POLQ is synergistic. Our data has the potential to uncover novel biomarker-driven drug therapy of POLQ inhibitors in R/R MCL. Citation Format: Jithma Prasad Abeykoon, Shuhei Asada, Kalindi Parmar, Xiaosheng Wu, Thomas Witzig, Geoffrey Shapiro, Alan D. D'Andrea. Targeting DNA polymerase theta and ATM leads to synergistic killing of mantle cell lymphoma cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6208.

Key Points Urinary TIMP2×IGFBP7 (uTIMP2×IGFBP7) concentrations experienced a rapid and sustained decline after high-dose methotrexate (MTX) exposure. uTIMP2×IGFBP7 kinetics and concentrations after high-dose MTX exposure demonstrated no utility in predicting AKI.

Abstract Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can result in a cytokine storm that is associated with poor outcomes in patients. The activation of a NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome following SARS-CoV-2 infection has been shown to play a major role in inflammatory immune responses. In this study, we show that open reading frame 8 (ORF8) protein is abundantly secreted as a glycoprotein in vitro. The glycosylated ORF8 stimulates human CD14+/CD16+ monocytes to cause upregulation of proinflammatory cytokine production and cell surface marker expression within 24 hours. The data suggests that stimulation of human monocytes by ORF8 is not receptor mediated. Rather, ORF8 is likely phagocytosed by human monocytes. ORF8 then stimulates the monocytes by independently binding to the NACHT and LRR domains of the NLRP3 protein. Pharmacologic inhibition of NLRP3 significantly diminished the production of pro-inflammatory cytokines from ORF8-stimulated human monocytes. Finally, this study shows that the ORF8 protein is also secreted in patients with newly diagnosed coronavirus disease 2019 (COVID-19). Levels of ORF8 in the blood of patients diagnosed with COVID-19 correlated with disease mortality and trajectory of disease. ORF8 stimulation of monocytes causes pro-inflammatory cytokine production that leads to the development of severe COVID-19.

AbstractWaldenström macroglobulinemia (WM) is a rare, indolent lymphoma, that predominately affects the elderly. We report the outcomes of young WM patients, evaluated over five decades, compared to their older counterparts, matched for the time of diagnosis. Between January 1, 1960 and October 31, 2013, 140 (11.8%) WM patients were ≤50 years of age at diagnosis in our database, and their estimated 10‐year overall survival (OS) was 74%, with death attributable to WM in a higher proportion of patients compared to their older (≥65 years) counterparts (91% vs. 58%, p = .0001). Young patients were grouped into three cohorts based on the timing of the initiation of therapy: Group 1 (1960–1977, n = 12), Group 2 (1978–1995, n = 48), and Group 3 (1996–2013, n = 74). Among young patients, there was no disease‐specific survival (DSS) difference across the three periods, [median DSS at 13 years (95% CI 5–23), 16 years (95% CI 14–22), and 15 years (95% CI 10‐NR; p = .41), respectively]. However, DSS for the older cohort incrementally improved (Group 1, median 5.2 years, Group 2: 9.6 years, Group 3: 12 years; p = .05) over these periods. The estimated average years‐of‐life lost for the young cohort was 11.2 years from diagnosis, based on the expected survival for a normal age‐ and sex‐matched population. Despite a protracted disease course, nearly all young patients succumb to their disease. In contrast to the improved survival of the elderly patient population, the evolving treatment strategies in WM have not impacted the outcome of young patients; however, the impact of Bruton tyrosine kinase inhibitors on this unique patient population remains to be determined.

Abstract Although extensively studied, the exact mechanism by which TGF-β mediates T-cell inhibition is not entirely clear. When we examined the effect of TGF-β on the phenotype and function of T cells, we noted that CD70 was significantly up-regulated by TGF-β. This surprising finding led us to explore the underlying mechanism by which TGF-β upregulates CD70 expression on T cells and to define the function of CD70+ cells in B-cell NHL. Interestingly, we observed that TGF-β preferentially induced CD70 expression on effector memory T cells while it predominantly up-regulated Foxp3 on naïve T cells. CD70 induction is Smad3-dependent and involves Stat5 signaling. CD70+ T cells were highly susceptible to TGF-β-mediated apoptosis and that transfection of Jurkat cells with the CD70 gene led to a significantly reduced survival. TGF-β-induced CD70+ T cells had a diminished response to immune stimulation associated with downregulation of co-stimulatory molecules CD27 and CD28. CD70-expressing T cells from biopsy specimens of patients with B-cell NHL failed to produce cytokines and displayed no signal transduction when stimulated. CD70-expressing T cells were highly represented in follicular NHL biopsy specimens and increased numbers of CD70+ cells correlated with an inferior patient outcome. These novel findings not only revealed a biological role for a TGF-β/CD70 axis in mediating immune inhibition, but also may lead to therapeutic approaches in patients with B-cell NHL.

Abstract Insulin-like growth factors (IGF-I, IGF-II) have long been recognized as important mitogens in many types of malignancies. Because the role of IGFs in growth control of myeloma cells has not been extensively examined, we have used a panel of IL-6-responsive myeloma cell lines to address this issue. Initial studies demonstrated that IGF-I and IGF-II significantly enhanced DNA synthesis by each of the four cell lines, even when assayed in the absence of IL-6. The specificity of the IGF response was confirmed using an IGF-I receptor Ab, and additional studies demonstrated that IGF responsiveness did not result from induction of autocrine IL-6 expression. When IL-6 responsiveness was assayed, three of four cell lines synthesized DNA in response to IL-6 alone; however, the magnitude of responsiveness was greatly enhanced by addition of IGFs. Similar results were obtained when proliferation and cell cycle progression were analyzed. By contrast, the KP-6 cell line was responsive to IL-6 only when IGF was present. Finally, we analyzed the effects of IGF-I on normal B lymphocytes. IGF, however, did not stimulate B cell DNA synthesis, suggesting that IGF responsiveness may represent a key difference between normal and malignant B cells. In summary, these studies suggest that IGFs may play an important role in multiple myeloma by virtue of their ability to directly stimulate tumor cell growth as well as modulate the magnitude of IL-6-driven growth.